Axial Flux Submersible Electric Motor

ABSTRACT

A pump system for pumping production fluids from a wellbore or pumping well treatment fluids into a wellbore comprising: an axial flux electric motor; a seal section coupled to the axial flux motor; a pump intake coupled to the seal section; a pump coupled to the pump intake, and a fluid discharge coupled to the pump. The torque capacity axial flux motor may be modified without removing the axial flux motor from the pump.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119(e) to U.S.Provisional Patent Application No. 63/007,052 filed on Apr. 8, 2020 andentitled “Axial Flux Submersible Electric Motor,” the disclosure ofwhich is hereby incorporated herein by reference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO A MICROFICHE APPENDIX

Not applicable.

BACKGROUND

The present application is related to pumps used to lift fluids from theground or inject fluids into the ground and, more specifically, theelectric motors used to power the pumps.

Natural resources can be recovered from subterranean formations forexample by drilling a wellbore to access the subterranean formations.Often the natural resources initially flow to surface via the wellboredue to formation pressure in the subterranean formations. As theproduction of natural resources continues, the formation pressuredecreases until a method of artificial lift may be required. An electricsubmersible pump placed in the wellbore is one artificial lift methodutilized to lift formation fluids such as hydrocarbons from the wellboreto surface.

Electric submersible pumps rely on electricity to power the electricmotor attached to the pump section. Typically these motors have reliedon a traditional and less efficient motor construction. Ongoing interestexists in utilizing electric motors that conserve electricity byimproving the efficiency of the motors.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure, referenceis now made to the following brief description, taken in connection withthe accompanying drawings and detailed description, wherein likereference numerals represent like parts.

FIG. 1 is a cut-away illustration of an embodiment of a pump system.

FIG. 2 is a side view drawing showing the magnetic flux flow from anembodiment of an axial gap motor.

FIG. 3 is a perspective view showing a rotor of an axial gap type motoraccording to an embodiment of the present invention.

FIG. 4 is a perspective view showing a stator of an axial gap type motoraccording to an embodiment of the present invention.

FIG. 5 A-D is a perspective view showing an embodiment of a statorstructure according to the present invention.

FIG. 6 A-H is a perspective view showing an axial gap type motor of anembodiment according to the present invention.

FIG. 7 A-D is a sectional view showing the rotors and stators of theaxial gap type motor according to an embodiment of the presentinvention.

FIG. 8 is a sectional view showing the rotors and stators of the axialgap type motor according to an embodiment of the present invention.

DETAILED DESCRIPTION

It should be understood at the outset that although illustrativeimplementations of one or more embodiments are illustrated below, thedisclosed systems and methods may be implemented using any number oftechniques, whether currently known or not yet in existence. Thedisclosure should in no way be limited to the illustrativeimplementations, drawings, and techniques illustrated below, but may bemodified within the scope of the appended claims along with their fullscope of equivalents.

Conventional electric submersible pump manufacturers have long utilizeda standard radial flux motor to power the pump. The standard radial fluxmotor utilizes electromagnetic coils for the stator wound axially fromthe head to the base. These head to base wound coils generate themagnetic flux that turn the rotor. The rotor is inside the stator sothat the magnetic flux is oriented radially away from the central axis.The long head to base wound coils of the radial stator result in somenon-active sections, called overhang, away from the rotor that do notproduce usable magnetic flux to the rotor and reduce the efficiency byincreasing the resistive heat generated by the electric current. Theradial flux electric motors also produce a smaller amount of torquebecause the magnetic flux is inside the stator between the rotor andstator.

Compared to a similar size radial flux electric motor, axial fluxelectric motors develop more torque with a higher efficiency while usingless material. In an axial flux motor, the rotor and stator are diskshapes that are stacked side-by-side with a common axis. The rotor andstators alternate from rotor to stator with the stator held staticwithin the housing. The rotor turns within the housing with the magneticflux traveling axially between rotor and stator. The permanent magnetaxial flux electric motor has a disk shaped stator with small windingsthat align with permanent magnets on the rotor. The smallelectromagnetic windings are smaller than the long axially wound statorsof the radial flux motors and have little to no non-active sections andgenerate less heat.

Disclosed herein is a pumping system for use with oil well operationsutilizing an axial flux motor powered by an electric power source. Thepumping system may be used to treat a well or produce a well. Thepumping system uses a controller with an electric power source to poweran axial flux motor to pump fluids into or out of an oil well.

Turning now to FIG. 1, illustrated is an embodiment of a pump system 100that may be utilized as a submersible pump, e.g., an electricalsubmersible pump (ESP), to lift production fluids from the well to thesurface. The well 10 may have a wellbore 2 drilled through the earth toa hydrocarbon bearing formation 4. Perforations 6 in the casing 8 enablethe fluid in the hydrocarbon bearing formation 4 to enter the casing 8.Production tubing 12 extends from the surface to support pump system 100at a depth proximate the perforations 6.

The pump system 100 may include a pump assembly 20, transmissionassembly 30, seal section 40, axial flux motor 50, controller 60, sensorarray 70, and heat exchanger system 90, each of which may be coupledtogether using suitable connectors such as bolted flange connectors,threaded connectors, etc. An electrical power source 64 may be connectedto the controller 60 by transmission cables 66. The controller 60provides electric power through power cables 62 to the axial flux motor50 to rotate the pump assembly 20 while monitoring the sensor array 70for feedback on the motor condition and fluid properties at the pumpintake and exit. Alternatively, the controller 60 can be locateddownhole, for example proximate other downhole components of the pumpsystem 100. The pump assembly 20 has a pump intake assembly 22 and apump discharge 24 attached to production tubing 12 to transport theproduction fluids to surface. In an embodiment, the axial flux motor 50has a heat exchanger system 90 such as a circulating oil system toremove the heat generated by the axial flux motor 50.

The controller 60 may change the pump operation based on user inputs,the data provided by the sensor array 70, or both. In an embodiment, thecontroller 60 may comprise a variable speed drive system that monitorsthe feedback from the sensor array 70 and adjusts the voltage and/orcurrent output to maintain a constant motor torque. The sensor array 70may include a pump intake pressure sensor, a pump discharge pressuresensor, wellbore fluid property indicators (e.g. pressure, temperature,viscosity, density, fluid phase condition, and solids content), a motortemperature sensor, a motor voltage feedback, a motor torque indicator,a current monitor, and shaft rotational position indicator. The sensorarray 70 may include a rotary encoder, also called a shaft encoder,located along the rotary shaft in one or more locations including thepump assembly 20, the transmission assembly 30, the seal section 40, theaxial flux motor 50, or the heat exchanger system 90. The rotary encodermay provide data on the angular motion of the rotary shaft includingposition, speed, distance, or any combination thereof. The rotaryencoder may be an absolute rotary encoder that indicates the currentshaft position (e.g., an angular transducer) or an incremental encoderthat provides information about the motion of the shaft, which typicallyis processed into information such as rotational position, speed, andangular distance. By way of example, the rotary encoder can be anelectro-mechanical device that converts angular position or motion ofthe shaft/axle to analog or digital output signals. The controller maycontrol operation of the axial flux motor 50 to account for varyingdownhole operational conditions or loads. For example, the controller 60may provide voltage or current to one stator for pump operations thatrequire a low amount of torque; e.g., motor or pump diagnostics. Thecontroller 60 may provide voltage or current to two or more stators, butnot all stators for pump operations to avoid damaging pump components byproviding excessive torque; e.g., over-torqueing the shaft. Thecontroller 60 may provide voltage or current to one or more assembliesof rotor(s) and stator(s) (which may also be referred to as a module ofrotor(s) and stator(s)), but not all assemblies of rotor(s) andstator(s) to isolate a damaged winding in a stator; e.g., a faultedwinding. The controller 60 may change the voltage or current supplied tothe axial flux motor 50 based on the data supplied by one or moresensors and/or user inputs to maintain a constant torque, change thepump rate, begin operation, or to shut down.

The pump assembly 20 may be a centrifugal type pump with a rotatingimpeller inside of a stationary diffuser rotating at a speed so that thefluid is pressurized. The pump assembly 20 may have a single impeller ormultiple impellers inside multiple diffusers to develop enough headpressure to convey the production fluid through the production tubing 12to the surface. The pump assembly 20 may comprise any type ofcentrifugal pump including a single or multistage deep well turbine,radial, axial flow impeller (e.g., propeller) or mixed flow type, multivane pump, or helicon axial type hybrid pump. The pump assembly 20 mayalso be a progressing cavity pump, gear pump, screw pump, double screwpump, or any other rotating pump, such pumps sized and configured to beplaced in a wellbore and mechanically coupled to the axial flux motor50.

The pump intake assembly 22 may include a gas separator, a sand trap, afluid modulating system, or other type of intake system. The pump intakeassembly 22 on the pump assembly 20 may have a gas separator to removeall or a fraction of the produced gas before the reservoir fluid entersthe pump assembly 20. Likewise, the pump intake assembly 22 may includea sand trap to remove all or a fraction of sand or debris from theproduced fluids. The pump intake assembly 22 may also have a check valvethat permits flow in one direction (e.g., from the wellbore into thesuction of the pump).

The pump discharge 24 may include a check valve that permits flow fromthe pump to the production tubing 12 but prevents flow from theproduction tubing 12 to enter the pump assembly 20. The check valve maybe a flapper valve, poppet valve, ball and seat, or any other type ofcheck valve known to those skilled in the arts. The pump discharge 24may include a debris diverter that prevents debris from falling backinto the pump discharge 24. The debris diverter may divert the tubingflow to an annular flow through a screened section then direct the flowback to the tubing.

A seal section 40 may include one or more sealing assemblies thatsealingly engage a rotary shaft to isolate the wellbore fluids from theinside of the axial flux motor 50. The seal section 40 may include athrust bearing to isolate the axial flux motor 50 from the downwardreaction force from the pump assembly 20. An upper end of the sealsection 40 may couple a lower end of the pump intake assembly 22, and alower end of the seal section 40 may couple to an upper end of the axialflux motor 50.

A transmission assembly 30 (e.g., a gear box) may optionally be used toprovide additional mechanical advantage (e.g., speed and/or torqueadjustments) between the seal section 40 and the pump assembly 20. Thetransmission assembly 30 may be attached between pump intake assembly 22and the seal section 40. The transmission assembly 30 may include one ormore gears and gear trains to adapt the torque and rotational speed ofthe motor to the pump assembly 20.

Optionally, the axial flux motor 50 may have a heat exchanger system 90to remove the heat generated in the axial flux motor 50 by transferringthe heat to the ambient wellbore environment, for example by utilizing aheat conductive material and a radiant geometry such an extended housingor fins. In an aspect, the heat exchanger system 90 may include adielectric coolant commonly referred to as oil. The axial flux motor 50may have an internal pump to circulate oil through the motor assembly tocool and lubricate the axial flux motor 50. Although the term oil isused it is understood that any dielectric fluid may be used as acoolant: mineral oil, synthetic oil, castor oil, silicone oil, and anycombination of oils. In an embodiment, the heat exchanger systemcirculates oil though the motor and radiates the heat through a housingmade of corrosion resistant and heat conductive materials. The housingmay be made from corrosion resistant materials such as stainless steels,nickel alloy steels, specially designed polymer, other corrosionresistant materials, or combinations of heat conductive and corrosionresistant materials. In an embodiment, the heat exchanger system 90 maycirculate the oil through the axial flux motor 50 to transfer the heatthrough the motor housing to the ambient wellbore fluid surrounding thehousing. The ambient wellbore fluid surrounding the axial flux motor 50may be cooler than the operating temperature of the axial flux motor 50and cool the oil before being recirculated back through the axial fluxmotor 50. In an embodiment, the heat exchanger system 90 may include anoil reservoir to exchange heat with the ambient wellbore fluid. The heatexchanger system 90 may include an oil pump to circulate the oil. In anembodiment, the internal oil pump may be integral to the axial fluxmotor 50 or powered by the axial flux motor 50. In an embodiment, theremay be two or more internal oil pumps. In an aspect, the heat exchangersystem 90 may comprise a refrigeration loop to cool the circulated oil,as described in more detail herein with reference to FIG. 7D. Whenpresent, an upper portion of heat exchanger system 90 may couple a lowerend of the axial flux motor 50, and a lower end of the heat exchangersystem 90 may couple to an upper end of the sensor array 70. If the heatexchanger system 90 is not present, a lower end of the axial flux motor50 may couple to an upper end of the sensor array 70.

The axial flux motor 50 may be used to power the pump assembly 20. Anaxial flux motor may use permanent magnets in the rotor to rotate therotor with rotating magnetic fields generated by the stator. Thisrotating magnetic field repels and attracts the magnetic force producedby the permanent magnets in the rotor to cause rotation of the rotor andthe attached rotary shaft. The rotor supplies the torque and rotation ofthe rotor and attached rotary shaft. An axial flux motor 50 includes arotor and stator with planar faces that are disk shape with an axis ofrotation perpendicular to the planar face and parallel to a rotationalshaft. The axial flux motor 50 may have a single rotor and stator, asingle rotor with two stators, two rotors with a single stator, ormultiple rotor and stator configurations.

Referring now to FIG. 2-4, an embodiment of axial flux motor 200 mayhave a single rotor 202 and a single stator 206. The rotor 202 andstator 206 may be mounted in a housing (e.g., sized and configured forplacement in a wellbore) with the rotor front surface 204 facing thestator front surface 207 separated by axial gap 214. The rotor 202 has arotary shaft 212 perpendicular to the rotor front surface 204. Rotor202, as detailed in FIG. 3, may have a plurality of permanent magnets216 angularly distributed about the rotor disk 218. The stator 206,shown in FIG. 4, has a plurality of stator windings 208 mounted onstator core 210. The position of the stator windings 208 across theaxial gap 214 to the rotor front surface 204 provides a path for theaxial flux Φ to generate torque. As shown in FIG. 2, the axial flux Φ issubstantially parallel to a central axis of the rotary shaft 212. Anaxial direction can be defined as parallel to a central axis of rotaryshaft 212, a radial direction can be defined as perpendicular to thecentral axis of rotary shaft 212 (e.g., extending from central axis ofrotary shaft 212 to the circumference of the rotor 202), and an angulardirection, distribution, position, or the like can be measured indegrees (e.g., 90, 180, 270, etc.) of a 360 degree circle perpendicularto the central axis of rotary shaft 212.

The rotor 202, shown in FIG. 3, may have a plurality of permanentmagnets 216 mounted onto the surface of a rotor disk 218 or permanentmagnets 216 mounted or fixed into the rotor disk 218. The magnets may bemade of neodymium-iron-boron, samarium-cobalt, Alnico, strontiumferrite, or other permanent magnet materials. The permanent magnets 216may be arranged radially and spaced angularly to account for the radialand angular position of the stator windings 208. The permanent magnets216 may be wedge-shaped or any other shape to take advantage of theshape of the magnetic field of the stator 206. The polarity of thepermanent magnets 216 may be varied based on the angular position on therotor disk 218. The rotary shaft 212 may be constructed of a highstrength non-magnetic alloy such as titanium, stainless steel, or nickelalloys (e.g., Inconel, Incoloy, Hastlelloy, or Monel).

The stator 206, shown in FIG. 4, may have a plurality of stator windings208 angularly spaced on a stator core 210 separated by gap 226. Eachstator winding 208 may have an electromagnet coil 224 wound about astator winding core 222 on a coil insulator 220. The electromagnet coil224 may be composed of a copper conductor with high temperatureinsulator materials for high temperature environments. High temperaturepolymeric insulation made from inorganic polymer materials may have sucha temperature ranging from about 150 C to about 300 C, alternatively aceramic coating or liner insulation may have such a temperature rangingfrom about 300 C to about 500 C. In various embodiments, the number ofstator windings 208 does not equal the number of permanent magnets 216.In an embodiment, the stator 206 may have two more stator windings 208than the rotor has permanent magnets 216. In an embodiment, the stator206 may have four more stator windings 208 than the rotor has permanentmagnets 216. The stator 206 may have any number of stator windings 208compared to the number of permanent magnets 216 without departing fromthe spirit or scope of the present disclosure, including withoutlimitation 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or more number of statorwindings in excess of the number of permanent magnets 216. In anembodiment, the stator 206 may have two less stator windings 208 thanthe rotor has permanent magnets 216. In an embodiment, the stator 206may have four less stator windings 208 than the rotor has permanentmagnets 216. The stator 206 may have any number of stator windings 208compared to the number of permanent magnets 216 without departing fromthe spirit or scope of the present disclosure, including withoutlimitation 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or more number of statorwindings less than the number of permanent magnets 216.

Referring to FIG. 2, the path for the magnetic flux Φ to generate torquewithin axial flux motor 200 is illustrated. This magnetic flux Φ isemitted from the stator winding 208 on stator 206 and influences thepermanent magnet 216 magnetic field on rotor 202 across the axial gap214. The magnetic flux Φ passes from the stator winding 208 crossesacross the axial gap 214 to the rotor front surface 204, (axial beingdefined as the direction parallel to the axis of the rotary shaft) andthus is referred to as “axial flux” with reference to the axial fluxmotor utilizing same. The stator windings 208 produce a magnetic field209A-C when an electric current is applied to the electromagnet coil224. The magnetic field 209A-C can provide alternating magnetic polesspaced a radial distance apart that is perpendicular to the central axisof rotary shaft 212. The magnetic fields 217A-B of the permanent magnets216 are alternately attracted or repulsed relative to the magnetic fieldof the stator windings 208 producing rotation of the rotor 202.

An alternate embodiment for the stator 230 is shown in FIG. 5A with aslotted core. The stator core 232 has slots or channels 234 formedradially and distributed about the circumference. The channels 234 areformed radially across the front surface 240 and back surface 244 andaxially across the top surface 238 and bottom surface 242 to form aunitary channel about the stator core 232. A plurality of channels 234are distributed around the circumference of the stator core 232.Electromagnetic windings 236 are in the radial direction are placed inthe channels 234.

An alternate embodiment for the stator 250 is shown in FIG. 5B with anon-slotted core. The stator core 252 may have electromagnetic windings254 that are wound in the radial direction for a partial torus shapeabout the stator core 252. The electromagnetic windings 254 may be thesame width across the bottom surface 256 and top surface 259 of thestator core 252. The gap 267 between electromagnetic windings 254 may belarger near the top surface 259 than near the bottom surface 256 acrossthe front surface 261 and back surface 264 of the stator core 252.

An alternate embodiment for the stator 271 is shown in FIG. 5C with anon-slotted core. The stator core 272 may have electromagnetic windings274 that are wound in the radial direction for a partial torus shapeabout the stator core 272. The electromagnetic windings 274 form a wedgeshape with a smaller width across the bottom surface 276 and a largerwidth across the top surface 278 of the stator core 272. The gap 281between the electromagnetic windings 274 may be the same width along thefront surface 282 and back surface 284 of the stator core 272.

An alternate embodiment for the stator 290 is shown in FIG. 5D withstator winding 292 mounted on the front surface 294 and back surface 296of the stator core 298. A plurality of stator windings 292 are angularlyspaced on a stator core 298 separated by gap 299. Each stator winding292 may have an electromagnet coil 302 wound about a stator winding core304 on a coil insulator 306.

The axial flux motor 200 may be configured with rotor 202 and stator 206arranged as shown in FIG. 6A-E. The rotor 202 has a rotary shaft 212(not shown) that extends out of the motor housing (not shown) totransfer rotational torque from the magnetic flux. The stator 206 has aset of electromagnetic windings that generate a magnetic force fromapplied electrical current.

The first rotor stator combination 310 is illustrated in FIG. 6A has asingle axial gap 214 with a single rotor 202 and single stator 206. Therotor 202 may have permanent magnets 216 mounted to the back surface 211of the rotor disk 218. The stator 206 has electromagnetic coils 224mounted to the stator front surface 207 facing the rotor 202. Themagnetic flux Φ travels across a single axial gap 214 to generaterotational torque. Although one stator configuration is shown for stator206, any stator configuration shown in FIG. 4 or FIG. 5 may be used.

An alternate rotor stator combination 320 is illustrated in FIG. 6B hastwo axial gaps 214A and 214B with rotor 202 and two stators 206A and206B. The rotor 202 may have permanent magnets 216 mounted to the rotorfront surface 204 and back surface 211 of the rotor disk 218 orpermanent magnets 216 mounted within the rotor disk 218. The stator 206Aand 206B has electromagnetic coils 224 mounted to the surface facing therotor 202. The magnetic flux Φ travels across two axial gaps 214A and214B to generate rotational torque. Although one stator configuration isshown for stator 206A and 206B, any stator configuration shown in FIG. 4or FIG. 5 may be used.

An alternate rotor stator combination 330 is illustrated in FIG. 6C hastwo axial gaps 214A and 214B with two rotors 202A and 202B and stator230. The rotor 202A may have permanent magnets 216 mounted to the backsurface 211A of the rotor disk 218A or permanent magnets 216 mountedwithin the rotor disk 218A. The rotor 202B may have permanent magnets216 mounted to the front surface 204B of the rotor disk 218B orpermanent magnets 216 mounted within the rotor disk 218B. The stator 230has electromagnetic windings 236 wound through the slots that develop amagnetic field on the front surface 240 and back surface 244 of thestator core 232. The magnetic flux Φ travels across two axial gaps 214Aand 214B to generate rotational torque. Although one statorconfiguration is shown for stator 230, any stator configuration shown inFIG. 4 or FIG. 5 may be used.

An alternate rotor stator combination 340 is illustrated in FIG. 6D hasfour gaps 214A-D with three rotors 202A-C and two stators 230A and 230B.The rotor 202A may have permanent magnets 216 mounted to the backsurface 211A of the rotor disk 218A or permanent magnets 216 mountedwithin the rotor disk 218A. The rotor 202B may have permanent magnets216 mounted to the front surface 204B and back surface 211B of the rotordisk 218A may have permanent magnets 216 mounted within the rotor disk218B. The rotor 202C may have permanent magnets 216 mounted to the frontsurface 204C of the rotor disk 218A or permanent magnets 216 mountedwithin the rotor disk 218C. The stator 230A and 230B has electromagneticwindings 236 wound through the slots that develop a magnetic field onthe front surface 240A and 240B and back surface 244A and 244B of thestator core 232A and 232B. The magnetic flux Φ travels across four axialgaps 214A, 214B, 214C, and 214D to generate rotational torque. Althoughone stator configuration is shown for stator 230A and 230B, any statorconfiguration shown in FIG. 4 or FIG. 5 may be used.

An alternate rotor stator combination 350 is illustrated in FIG. 6E hassix gaps 214A-F with four rotors 202A-D and three stators 230A-C. Themagnetic flux Φ travels across six axial gaps 214A, 214B, 214C, 214D,214E, and 214F to generate rotational torque. Although one statorconfiguration is shown for stator 230A-C, any stator configuration shownin FIG. 4 or FIG. 5 may be used.

An alternate rotor stator combination 360 is illustrated in FIG. 6F hasthree gaps with two axial gaps 214A-B and one radial gap 258 with onerotor 270 and two axial stators 206A and 206B and one radial stator 260.The rotor 270 may have an axial set of permanent magnets 257 mounted tothe front surface 255 and back surface of the rotor disk 251 orpermanent magnets 257 mounted within the rotor disk 251. The rotor 270may have radial permanent magnets 253 mounted to the top surface 265 ofrotor disk 251. The stator 206A and 206B have axial gaps 214A and 214Bwith the rotor 270. The stator 206A and 206B are parallel to rotor 270and have electromagnetic coils 224 mounted to the surface facing therotor 270. The magnetic flux Φ travels across two axial gaps 214A and214B to generate rotational torque. The radial stator 260 has a radialgap 258 with the rotor 270. The radial stator 260 is perpendicular tothe axis of rotation and aligned with the top surface 265 of rotor 270.The radial stator 260 has a stator core 262 with electromagnetic coils266 mounted onto stator windings 263 aligned to face the rotor 270. Themagnetic flux Φ from stator 260 travels radially across radial gap 258to generate rotational torque. Although radial stator 260 and 206A-B areshown, any stator configuration shown in FIG. 4 or FIG. 5 may be used.

An alternate rotor stator combination 370 is illustrated in FIG. 6G hasthree gaps with two axial gaps 214A-B and one radial gap 258 with onestator 250 and rotors 202A and 202B and one radial rotor 280. In thisembodiment the stator 250 may be connected to an axial shaft (not shown)to rotate within the axial rotors 202A-B and radial rotor 280. Theradial rotor 280 and rotors 202A and 202-B are mechanically connectedand are not fixed to the housing and do rotate. The rotor 202A may havepermanent magnets 216 mounted to the back surface 211A of the rotor disk218A or permanent magnets 216 mounted within the rotor disk 218A. Therotor 202B may have permanent magnets 216 mounted to the front surface204B of the rotor disk 218B or permanent magnets 216 mounted within therotor disk 218B. The stator 250 may have a non-slotted stator core 252with electromagnetic windings 254 that are wound in the radial directionfor a partial torus shape about the stator core 252. The stator 250 hasaxial gap 214A and 214B with the rotors 202A and 202B. The stator 250 isparallel to rotor disk 218A and rotor disk 218B. The magnetic flux Φtravels across two axial gaps 214A and 214B to generate rotationaltorque. The stator 250 has a radial gap 258 with the radial rotor 280.The radial rotor 280 is perpendicular and aligned with the top surface259 of stator 250. The rotor 280 has a rotor core 283 with permanentmagnets 286 mounted onto inner surface 288 aligned with outer surface269 the stator 250. The magnetic flux Φ from stator 250 travels radiallyacross gap 258 to generate rotational torque. Although stator 250 isshown, any stator configuration shown in FIG. 4 or FIG. 5 may be used.

An alternate rotor stator combination 380 is illustrated in FIG. 6H hasthree gaps with two axial gaps 214A-B and one radial gap 258 with stator250, stators 206A, 206B, and one radial stator 260. In this embodimentthe stator 250 may be connected to an axial shaft (not shown) to rotatewithin the axial stators 206A-B and radial stator 260. The radial stator260 and axial stators 206A and 206B are fixed to the housing (not shown)and do not rotate. The stator 250 may have a non-slotted stator core 252with electromagnetic windings 254 that are wound in the radial directionfor a partial torus shape about the stator core 252. The stator 206A and206B have axial gap 214A and 214B with the stator 250. The stator 206Aand 206B are parallel to stator 250 and have electromagnetic coils 224mounted to the surface facing the stator 250. The magnetic flux Φtravels across two axial gaps 214A and 214B to generate rotationaltorque. The radial stator 260 has a radial gap 258 with the stator 250.The radial stator 260 is perpendicular and aligned with the top surface273 of stator 250. The stator 260 has a stator core 262 withelectromagnetic coils 266 mounted onto stator windings 263 aligned toface the electromagnetic coils 266. The magnetic flux D from stator 260travels radially across gaps 258 to generate rotational torque. Althoughradial stator 260 and stator 206A, 206B, and 250 are shown, any statorconfiguration shown in FIG. 4 or FIG. 5 may be used.

Turning now to FIG. 7A, an embodiment of an axial flux motor 400connected to a seal section 410 is described. The seal section 410 maybe attached to the axial flux motor 400 with one or more bolts 402.Although a bolt 402 is shown, any type of fastener may be utilized suchas screws, nuts, threads, etc. The seal section coupling 406 may bethreadingly engaged to the seal section shaft 408 and may have a slidingfit with splines to the rotary shaft 432.

The seal section 410 may include a bag seal, a labyrinth seal, a thrustbearing, debris exit ports, and thermal expansion chamber. The sealsection 410 has a housing 412 sealingly connected to (or formed integralwith) seal section base 411. A stationary thrust bearing surface 414 maybe attached to, embedded into, or integral with seal section base 411. Athrust disk 416 may be attached to seal section shaft 408 such that thethrust disk 416 rotates with the seal section shaft 408. The thrust disk416 may have rotating thrust bearing surface 418 and fluid port 420. Theshaft seal assembly 422 may have one or more labyrinth seal, inflatedbag seal, or both. The shaft seal assembly 422 may have multiplelabyrinth seals, or inflated bag seals, or both in tandem.

The seal section 410 may have a rotating thrust bearing surface 418engaged with a stationary thrust bearing surface 414. The pump assembly20 may transfer a downward reaction force down the rotating shaft to theseal section shaft 408. The thrust disk 416 attached to the seal sectionshaft 408 transfers the force through the rotating thrust bearingsurface 418 to the stationary thrust bearing surface 414 to the sealsection base 411. The transfer of resultant downward force to the thrustbearing surfaces may isolate the axial flux motor 400 from the resultantdownward force.

The cooling oil from the axial flux motor 400 may fill the seal sectionchamber 424 and lubricate the rotary thrust bearing surface 418 andstationary thrust bearing surface 414.

The axial flux motor 400 may be connected to the seal section 410 bybolts 402 threadingly engaged into motor head end surface 434. The motorhousing 436 may contain front stator 440, front rotor 450, middle stator460, back rotor 470, back stator 480, and base 490. The front stator440, middle stator 460, and back stator 480 may be fixed to the motorhousing 436 and do not rotate.

Front stator 440 may have a plurality of stator windings 444 angularlyspaced on a stator core. Each stator winding 444 may have anelectromagnet coil 442 wound about a stator winding core. The frontstator 440 and front rotor 450 may be separated by gap 492. The frontrotor 450 may be attached to rotary shaft 432 or may be formed of aunitary body. The front rotor 450 rotates about a central axis of therotary shaft 432. The front surface 456 is perpendicular to the centralaxis of rotary shaft 432. A permanent magnet 454 may be mounted onto thefront surface 456 of a rotor disk 452 or permanent magnets 454 may bemounted or fixed into the rotor disk 452. The permanent magnets 454 arearranged radially and spaced angularly to account for the radial andangular position of the stator windings 444. The polarity of thepermanent magnets 454 is varied based on the angular position on therotor disk 452, which can be provided by the rotary encoder discussedherein. Although one stator configuration for front stator 440 is shown,any stator configuration shown in FIG. 4 or FIG. 5 may be used.

A middle stator 460 may be attached between a front stator 440 and backstator 480. The middle stator 460 may have a plurality ofelectromagnetic windings 462 about a stator core 464. Theelectromagnetic windings 462 may be wound in a radial direction for apartial torus shape about the stator core 464. The stator core 464 maybe slotted or channeled, or the stator core 464 may not be slotted. Theelectromagnetic windings 462 may be wound with the same width across thefront surface 466 and back surface 468. The electromagnetic windings 462may be wound with an angular shape with a constant gap between windings.The middle stator 460 is separated from the front rotor 450 by gap 494and the back rotor 470 by gap 496. Although one stator configuration isshown for middle stator 460, any stator configuration shown in FIG. 4 orFIG. 5 may be used.

The back rotor 470 may be attached to rotary shaft 432 or may be formedof a unitary body. The back rotor 470 rotates about an axis common tothe rotary shaft 432. The front surface 476 of back rotor 470 isperpendicular to the axis common to rotary shaft 432. A permanent magnet474 may be mounted onto the front surface 476 of a rotor disk 472 orpermanent magnets 474 may be mounted or fixed into the rotor disk 472.The permanent magnets 474 are arranged radially and spaced angularly toaccount for the radial and angular position of the electromagneticwindings 462. The polarity of the permanent magnets 474 is varied basedon the angular position on the rotor disk 472, which can be providedwith the rotary encoder discussed herein.

The back stator 480 may have a plurality of stator windings 484angularly spaced on a stator winding core 486. Each stator winding 484may have an electromagnet coil 482 wound about a stator winding core486. The back stator 480 and back rotor 470 may be separated by gap 498.Although one stator configuration for stator 480 is shown, any statorconfiguration shown in FIG. 4 or FIG. 5 may be used.

The axial flux motor 400 may be configured with four axial gaps with tworotors and three stators. The magnetic flux Φ may travel across gaps492, 494, 496, and 498 to generate rotational torque. The magnetic fluxΦ may be emitted from a stator across each gap 492, 494, 496, and 498and return to the emitting stator to influence the permanent magnets onthe rotor to induce rotation. The magnetic flux Φ may be emitted from astator and cross a gap, through a rotor, across a gap, to a stator andreturn to the emitting stator to influence the permanent magnets on therotor to induce rotation. The magnetic flux Φ may travel from one statorthrough one or more gaps to influence the permanent magnetics on therotors to induce rotation. The magnetic flux Φ may travel from stator440 across gap 492 to front rotor 450 and return across gap 492. Themagnetic flux Φ may travel from stator 440, across gap 492, throughfront rotor 450, across gap 494, to middle stator 460. The given fluxpath Φ may change depending on the type of stator and rotorconfiguration. The given flux path Φ may change depending on thepolarity of the rotor magnet in a stator and rotor configuration.Although two magnetic flux Φ paths have been described, it is understoodthat any rotor stator combination and any magnetic flux path may be usedwithout deviating from the disclosure.

The back stator 480 may be connected to base 490 and/or motor housing436, and base 490 can have internal bearings. Rotary shaft bearings 491may be located on the outer surface 493 of rotary shaft 432 and in abearing race 497 inside the base 490. The rotary shaft bearings 491 maybe configured to support the rotors, reduce vibration, and distributeradial and axial bearing loading. The rotary shaft bearings 491 may berolling element type bearings such as rotationally sliding sleevebearing, bushing bearings, ball bearings, roller bearings, sphericalroller, tapered roller, or needle roller. The rotary shaft bearings 491may be housed inside an open assembly that allows lubricating fluid toflow through or a closed assembly with a sealed structure. The rotaryshaft bearings 491 may be any of the listed configurations or anycombination thereof. The rotary shaft bearings 491 may be constructed ofbronze, steel alloy, nickel alloy, ceramics, graphite, compositematerials, or any combination thereof.

Although the rotary shaft bearings 491 are shown in one location, therotary shaft bearings 491 may be placed in multiple locations within theaxial flux motor 400. The rotary shaft bearings 491 may be placedbetween front rotor 450 and back rotor 470. The rotary shaft bearing 491may be placed adjacent to front surface and back surface of each rotor.Each of the rotary shaft bearings 491 placed in the axial flux motor 400may be the same type of bearing or may be multiple types of bearings.

In an alternate embodiment, the rotary shaft bearing 491 may be a thrustbearing. The rotary shaft bearing 491 may have a rotating thrust bearingsurface mated with a stationary thrust bearing surface (not shown). Theaxial flux motor 400 may have one or more thrust bearings and one ormore rotary shaft bearings 491, for example of the type shown in sealsection 410 of FIG. 7A.

In an aspect, all or a portion of the seal section 40 of FIG. 1 can beincorporated into a common housing with the axial flux motor 50, forexample disposed within a common housing or sub-assembly. Turning now toFIG. 7B, an embodiment of an axial flux motor 500 and seal section 510with a common rotary shaft 508 is described. In this embodiment, theseal section 510 and axial flux motor 500 may share a singular motorhousing 536 and a common rotary shaft 508. The motor housing 536 maycontain the seal section 510 (corresponding to one or more components ofseal section 410 of FIG. 7A) and the axial flux motor 500. A rotaryshaft 508 may extend from the front rotor 450 into the seal section 510.As shown in FIG. 7B, the seal section 510 comprises a thrust bearing514/516 and shaft seal assembly 522 within a common housing with theaxial flux motor 50. In an alternative embodiment, the thrust bearing514/516 is contained within a common housing with the axial flux motor50, and other components of the shaft seal assembly 522 may be containedwithin a separate housing that is mechanically connected (e.g., boltedor threaded) to the motor housing 536, for example as shown in FIG. 7A(e.g., housing 412 bolted to motor housing 436).

The seal section 510 may contain a bag seal, a labyrinth seal, a thrustbearing, debris exit ports, and thermal expansion chamber. A sealsection head 511 may be fixed to the motor housing 536. A stationarythrust bearing surface 514 may be attached to, embedded into, orintegral with seal section head 511. A thrust disk 516 may be attachedto rotary shaft 508 such that the thrust disk 516 rotates with therotary shaft 508. The thrust disk 516 may have rotating thrust bearingsurface 518 and fluid port 520. The shaft seal assembly 522 may have oneor more labyrinth seal, inflated bag seal, or both. The shaft sealassembly 522 may have multiple labyrinth seals, inflated bag seals, orboth in tandem.

The seal section 510 may have a rotating thrust bearing surface 518engaged with a stationary thrust bearing surface 514. The pump assembly20 may transfer a downward reaction force along the rotating shaft tothe rotary shaft 508. The thrust disk 516 attached to the rotary shaft508 transfers the force through the rotating thrust bearing surface 518to the stationary thrust bearing surface 514 to the seal section head511. The transfer of resultant downward force to the thrust bearingsurfaces may isolate the axial flux motor 500 from the resultantdownward force.

The cooling oil from the axial flux motor 500 may fill the seal sectionchamber 524 and lubricate the rotary thrust bearing surface 518 andstationary thrust bearing surface 514.

The axial flux motor 500 may be connected to the seal section 510 by anelongated motor housing 536. The motor housing 536 may contain frontstator 440, front rotor 450, middle stator 460, back rotor 470, backstator 480, and base 490. The front stator 440, middle stator 460, andback stator 480 may be fixed to the motor housing 536 and do not rotate.

The front rotor 450 may be attached to rotary shaft 508 or may be formedof a unitary body. The front rotor 450 rotates about a central axis ofthe rotary shaft 508. The front surface 456 is perpendicular to thecentral axis of rotary shaft 508. A permanent magnet 454 may be mountedonto the front surface 456 of a rotor disk 452 or permanent magnets 454may be mounted or fixed into the rotor disk 452. The permanent magnets454 are arranged radially and spaced angularly to account for the radialand angular position of the stator windings 444. The polarity of thepermanent magnets 454 is varied based on the angular position on therotor disk 452, which can be provided by the rotary encoder discussedherein. The front rotor 450 may be attached to middle rotary shaft 506or may be formed of a unitary body.

The front stator 440 may be attached to the seal section head 511 and/orthe motor housing 536. Front stator 440 may have a plurality of statorwindings 444 angularly spaced on a stator core. Each stator winding 444may have an electromagnet coil 442 wound about a stator winding core.The front stator 440 and front rotor 450 may be separated by gap 492.Although one stator configuration for front stator 440 is shown, anystator configuration shown in FIG. 4 or FIG. 5 may be used.

A middle stator 460 may be attached between a front stator 440 and backstator 480. The middle stator 460 may have a plurality ofelectromagnetic windings 462 about a stator core 464. Theelectromagnetic windings 462 may be wound in a radial direction for apartial torus shape about the stator core 464. The stator core 464 maybe slotted or channeled. The stator core 464 may not be slotted. Theelectromagnetic windings 462 may be wound with the same width across thefront surface 466 and back surface 468. The electromagnetic windings 462may be wound with an angular shape with a constant gap between windings.The middle stator 460 is separated from the front rotor 450 by gap 494and the back rotor 470 by gap 496. Although one stator configuration formiddle stator 460 is shown, any stator configuration shown in FIG. 4 orFIG. 5 may be used.

The back rotor 470 may be attached to middle rotary shaft 506 or may bemade from unitary construction. The back rotor 470 rotates about an axiscommon to the middle rotary shaft 506. The front surface 476 of backrotor 470 is perpendicular to the axis common to middle rotary shaft506. A permanent magnet 474 may be mounted onto the front surface 476 ofa rotor disk 472 or permanent magnets 474 may be mounted or fixed intothe rotor disk 472. The permanent magnets 474 are arranged radially andspaced angularly to account for the radial and angular position of theelectromagnetic windings 462. The polarity of the permanent magnets 474is varied based on the angular position on the rotor disk 472, which canbe provided with the rotary encoder discussed herein.

The back stator 480 may have a plurality of stator windings 484angularly spaced on a stator winding core 486. Each stator winding 484may have an electromagnet coil 482 wound about a stator winding core486. The back stator 480 and back rotor 470 may be separated by gap 498.Although one stator configuration for back stator 480 is shown, anystator configuration shown in FIG. 4 or FIG. 5 may be used.

The back stator 480 may be connected to base 490 and motor housing 536.Rotary shaft bearings 491 may be located on the outer surface 513 ofback rotary shaft 512 and in a bearing race 497 inside the base 490. Therotary shaft bearings 491 may be configured to support the rotors,reduce vibration, and distribute radial and axial bearing loading.

Although the rotary shaft bearings 491 are shown in one location, therotary shaft bearings 491 may be placed in multiple locations within theaxial flux motor 500. The rotary shaft bearings 491 may be placedbetween front rotor 450 and back rotor 470. The rotary shaft bearing 491may be placed adjacent to front surface and back surface of each rotor.Each of the rotary shaft bearings 491 placed in the axial flux motor 500may be the same type of bearing or may be multiple types of bearings.

Turning now to FIG. 7C, an embodiment of an axial flux motor 600, sealsection 610, and heat exchange system 620 is described. In thisembodiment, the seal section 610 and axial flux motor 600 may be inseparate housings that are releasably connected, for example as shownwith reference to bolts 402 and seal section coupling 406 of FIG. 7A, orthe seal section 610 and the axial flux motor 600 may share a commonhousing and shaft, for example as shown with reference to motor housing536 and rotary shaft 508 of FIG. 7B. An oil pump within the heatexchanger system 620 may circulate cooling oil through the axial fluxmotor 600. The axial flux motor 600 has an outer housing 660 thatexchanges heat from the cooling oil with the ambient wellbore.

The seal section 610 may contain a bag seal, a labyrinth seal, a thrustbearing, debris exit ports, and thermal expansion chamber within chamber622, for example (without limitation) as described with references toseal section 510 of FIG. 7B. The seal section head 511 may be fixed tothe inner housing 650 or may be releasably connected with removablefasteners as shown in FIG. 7A. The seal section 610 may be sealed to theaxial flux motor 600 with seals, continuous housing, or any other methodknown to those in the art.

The axial flux motor 600 may have an inner housing 650 and an outerhousing 660. The inner housing 650 may contain front stator 440, frontrotor 450, middle stator 460, back rotor 470, back stator 480, and oilpump section 495. The front stator 440, middle stator 460, and backstator 480 may be fixed to the inner housing 650 and do not rotate. Thefront stator 440, front rotor 450, middle stator 460, back rotor 470,back stator 480 can be configured and function as described withreference to the like components of FIG. 7A.

The front rotor 450 may be attached to rotary shaft 608 or may be formedof a unitary body. The front rotor 450 rotates about a central axis ofthe rotary shaft 608. The front surface 456 is perpendicular to thecentral axis of rotary shaft 608. The front rotor may have permanentmagnets as described in FIG. 7A. The front rotor 450 may be attached tomiddle rotary shaft 606 or may be formed of a unitary body.

The front stator 440 may be attached to the seal section head 611 andthe inner housing 650. Front stator 440 may have a plurality of statorwindings 444 angularly spaced on a stator core. Each stator winding 444may have an electromagnet coil 442 wound about a stator winding core.The front stator 440 and front rotor 450 may be separated by gap 492.Although one stator configuration for front stator 440 is shown, anystator configuration shown in FIG. 4 or FIG. 5 may be used.

A middle stator 460 may be attached between a front stator 440 and backstator 480. The middle stator 460 may have a plurality ofelectromagnetic windings 462 about a stator core 464. Theelectromagnetic windings 462 may be wound in a radial direction for apartial torus shape about the stator core 464. The stator core 464 maybe slotted or channeled, or the stator core 464 may not be slotted. Theelectromagnetic windings 462 may be wound with the same width across thefront surface 466 and back surface 468. The electromagnetic windings 462may be wound with an angular shape with a constant gap between windings.The middle stator 460 is separated from the front rotor 450 by gap 494and the back rotor 470 by gap 496. Although one stator configuration isshown for middle stator 460, any stator configuration shown in FIG. 4 orFIG. 5 may be used.

The back rotor 470 may be attached to middle rotary shaft 606 or may bemade from unitary construction. The back rotor 470 rotates about an axiscommon to the middle rotary shaft 506. The front surface 476 of backrotor 470 is perpendicular to the axis common to middle rotary shaft606. The back rotor 470 may contain permanent magnets as described withFIGS. 7A and 7B. The back rotor 470 may have a back rotary shaft 626attached to the back surface 468 of the rotor disk 472. The polarity ofthe permanent magnets 474 is varied based on the angular position on therotor disk 472, which can be provided with the rotary encoder discussedherein.

The back stator 480 may have a plurality of stator windings 484angularly spaced on a stator winding core 486. Each stator winding 484may have an electromagnet coil 482 wound about a stator winding core486. The back stator 480 and back rotor 470 may be separated by gap 498.Although one stator configuration for stator 480 is shown, any statorconfiguration shown in FIG. 4 or FIG. 5 may be used.

The back stator 480 may be connected to oil pump section 495 and innerhousing 650. The rotary shaft bearings 491 may be configured to supportthe rotors, reduce vibration, and distribute radial and axial bearingloading.

In an embodiment, the oil pump section 495 circulates oil through theaxial flux motor 600 to transfer the heat generated by theelectromagnetic coils.

Rotational motion of the back rotary shaft 626 provides the rotarymotion to the oil pump to pressurize the oil. The oil pumping mechanismmay be an impeller and diffuser, however any type of rotary pumpingmethod may be utilized: external gear pump, internal gear pump, lobepump, sliding vane pump, piston pump, single screw pump, double screwpump, single stage centrifugal pump, or multistage centrifugal pump, orany similar pump type.

Although the oil pump section 495 is shown attached the bottom of theaxial flux motor 600, the oil pump section 495 may be attached betweenthe axial flux motor 600 and the seal section 610. Although the impellerand diffuser is shown attached to the back rotary shaft 626, the oilpump may have a motor independent of the axial flux motor. Although theoil pump is shown as a separate impeller inside of a diffuser, the oilpump may be formed by vanes or impellers on the rotors.

Turning now to FIG. 7D, an embodiment of an axial flux motor 700, sealsection 710, and heat exchange system 720 is described. The embodimentof FIG. 7D is similar to the embodiment of FIG. 7C, except that the heatexchanger system 720 having a refrigeration assembly is shown anddescribed in FIG. 7D as an alternative to the heat exchanger system 620of FIG. 7C. In this embodiment, the axial flux motor 700 may be inseparate housings that are releasably connected, for example as shownwith reference to bolts 402 and seal section coupling 406 of FIG. 7A, orthe seal section 610 and the axial flux motor 600 may share a commonhousing an shaft, for example as shown with reference to motor housing536 and rotary shaft 508 of FIG. 7B. An oil pump within the heatexchanger system 720 may circulate cooling oil through the axial fluxmotor 700. The heat exchanger system 720 may have a refrigerationassembly to cool the oil circulated by an oil pump.

The seal section 710 may contain a bag seal, a labyrinth seal, a thrustbearing, debris exit ports, and thermal expansion chamber within chamber722, for example (without limitation) as described with reference toseal section 510 of FIG. 7B. The seal section head 511 may be fixed tothe motor housing 750 or may be releasably connected with removablefasteners as shown in FIG. 7A. The seal section 710 may be sealed to theaxial flux motor 700 with seals, continuous housing, or any other methodknown to those in the art.

The axial flux motor 700 may have a motor housing 750 containing a frontstator 440, front rotor 450, middle stator 460, back rotor 470, backstator 480, and oil pump section 495. The front stator 440, middlestator 460, and back stator 480 may be fixed to the motor housing 750and do not rotate. The front stator 440, front rotor 450, middle stator460, back rotor 470, back stator 480 can be configured and function asdescribed with reference to the like components of FIG. 7A.

The front rotor 450 may be attached to rotary shaft 708 or may be formedof a unitary body. The front rotor 450 rotates about a central axis ofthe rotary shaft 708. The front surface 456 is perpendicular to thecentral axis of rotary shaft 708. The front rotor may have permanentmagnets as described in FIG. 7A. The front rotor 450 may be attached tomiddle rotary shaft 706 or may be formed of a unitary body.

The front stator 440 may be attached to the seal section head 711 andthe motor housing 750. Front stator 440 may have a plurality of statorwindings 444 angularly spaced on a stator core. Each stator winding 444may have an electromagnet coil 442 wound about a stator winding core.The front stator 440 and front rotor 450 may be separated by gap 492.Although one stator configuration for front stator 440 is shown, anystator configuration shown in FIG. 4 or FIG. 5 may be used.

A middle stator 460 may be attached between a front stator 440 and backstator 480. The middle stator 460 may have a plurality ofelectromagnetic windings 462 about a stator core 464. Theelectromagnetic windings 462 may be wound in a radial direction for apartial torus shape about the stator core 464. The stator core 464 maybe slotted or channeled, or the stator core 464 may not be slotted. Theelectromagnetic windings 462 may be wound with the same width across thefront surface 466 and back surface 468. The electromagnetic windings 462may be wound with an angular shape with a constant gap between windings.The middle stator 460 is separated from the front rotor 450 by gap 494and the back rotor 470 by gap 496. Although one stator configuration isshown for middle stator 460, any stator configuration shown in FIG. 4 orFIG. 5 may be used.

The back rotor 470 may be attached to middle rotary shaft 706 or may bemade from unitary construction. The back rotor 470 rotates about an axiscommon to the middle rotary shaft 506. The front surface 476 of backrotor 470 is perpendicular to the axis common to middle rotary shaft606. The back rotor 470 may contain permanent magnets as described withFIGS. 7A and 7B. The back rotor 470 may have a rotary shaft 726 attachedto the back surface 468 of the rotor disk 472. The polarity of thepermanent magnets 474 is varied based on the angular position on therotor disk 472, which can be provided with the rotary encoder discussedherein.

The back stator 480 may have a plurality of stator windings 484angularly spaced on a stator winding core 486. Each stator winding 484may have an electromagnet coil 482 wound about a stator winding core486. The back stator 480 and back rotor 470 may be separated by gap 498.Although one stator configuration for stator 480 is shown, any statorconfiguration shown in FIG. 4 or FIG. 5 may be used.

The back stator 480 may be connected to oil pump section 495 and motorhousing 750. Rotary shaft bearings 491 may be configured to support therotors, reduce vibration, and distribute radial and axial bearingloading.

In an embodiment, the oil pump section 495 circulates oil from the axialflux motor 700 to a reservoir chamber with a refrigeration assembly 780comprising a refrigeration cycle and related components (e.g.,compressor, condenser, expansion valve, and evaporator). The oiltransfers the heat generated by the electromagnetic coils to an oilreservoir 734 configured to exchange heat with the cooling coil 784 ofthe refrigeration assembly 780.

The oil pump section 495 may have an impeller 724 inside of a diffusercavity 772. Rotational motion of the rotary shaft 726 turns the impeller724 inside of the diffuser cavity 772 to pressurize the oil. The oilpumping mechanism may be an impeller and diffuser, however any type ofrotary pumping method may be utilized: external gear pump, internal gearpump, lobe pump, sliding vane pump, piston pump, single screw pump,double screw pump, single stage centrifugal pump, or multistagecentrifugal pump, or any similar pump type.

The oil may be pressurized by the oil pump section 495 to flow throughexit port 774 and into the oil reservoir 734 defined by motor housing750, bottom housing end 752, partition 796, and oil pump cap end surface754. The oil may be cooled by cooling coil 784 before returning to themotor though ports 786 and into flow passage 788 (e.g., a hollow flowconduit inside rotary shaft 726). The cooling coil 784 generates acooling surface from the refrigeration assembly 780. The refrigerationassembly 780 includes a compressor 790 that compresses a refrigerantmixture such as a fluorocarbon, ammonia, or propane working fluid. Thecompressor 790 may be powered by the rotary shaft 726 or with asecondary motor. The compressed fluid passes from the compressor 790 tothe heat exchanger coil 792 that may be attached to the motor housing750. The compressed fluid may exchange heat with the heat exchanger coil792 that exchanges heat through the motor housing 750 to the ambientwellbore fluids outside of the motor housing 750. A partition 796 mayseparate the cooling compartment 756 with the cooling coil 784 from theheating compartment 758 with the heat exchanger coil 792. The compressedliquid refrigerant passes from the compressor 790 to the heat exchangercoil 792, through an expansion valve 794 where is expands to a gas andflows, into the cooling coil 784, then back to the compressor 790 forcompression into a liquid and continued circulation though therefrigeration cycle.

The oil flow may pass though the flow passage 788 and out through upperflow port 488 and lower flow port 487 to flow through the gaps betweenthe upper rotor, back rotor, and shaft to cool the stator coils andlubricate the axial and radial bearings.

Although the oil pump section 495 is shown attached the bottom of theaxial flux motor 700, the oil pump section 495 may be attached betweenthe axial flux motor 700 and the seal section 710.

Although the refrigeration assembly 780 and oil reservoir 734 is shownbelow the axial flux motor 700, the refrigeration assembly 780 and oilreservoir 734 may be located between the axial flux motor 700 and theseal section 710.

In an embodiment, the refrigeration assembly 780 and oil reservoir 734may be located in the seal section 710.

Although the embodiment of pump system 100 is described as a productionpump that pumps fluid from a well to a pipeline, the pump system 100 maybe an injection pump that pumps fluid from the surface into a wellbore.

Turning now to FIG. 8, a method of modifying an embodiment of axial fluxmotor 800, attached to a seal section and pump assembly, is described.One or more pair of rotors and stators may be added, removed, orreplaced from an axial flux motor. In an embodiment of axial flux motor800, an assembly (or module) of rotor(s) 830B and stator(s) 840B may beadded to an axial flux motor 800 that is attached to a seal section andpump assembly.

The axial flux motor 800 assembly before modification may include an endcap 820 connected to a seal section 893. End cap 820 and rotary shaft802 may be connected to seal section 893 by threads, fasteners, welding,other connecting parts (not shown), or any other method that may beutilized by those skilled in the art.

End cap 820 may be releasably connected to stator 840A with threads,fasteners, bolts or any other method. Rotary shaft 802 may be connectedto rotor 810 or may be a unitary body. Rotor 810 may have permanentmagnets 814 mounted onto the outer surface of rotor disk 812. Powercable terminal 920 may receive power cable 62 and be attached to end cap820. The power cable 62 may be attached to power cable terminal 920 byany mechanical connection method such as threading, bolting, welding, orcable connectors (not shown) that anchor and seal the power cable 62 tothe power cable terminal 920 or any other means that provides mechanicalstability. The power cable 62 may contain two, three, or more powerconductors 926 connected to two, three, or more releasable pinconnectors 922A. Although the power cable terminal 920, power cable 62,and releasable pin connectors 922A are illustrated as a separateassembly attached to the end cap 820, it is understood that the powercable terminal 920, power cable 62, and releasable pin connectors 922Amay be integrated into the end cap 820 or configured radially about thecircumference of the axial flux motor 800.

Stator 840A is connected to end cap 820 and stator 860 by threading,fasteners, other connecting parts (not shown), or a combination of anyof those methods. The stator 840A has electromagnetic windings 842Awound radially about a stator core 844A. The stator core 844A may beslotted or non-slotted. The electromagnetic windings 842A may be woundwith straight partial torus shape or with an angular partial torusshape. Power transfer terminal 940A may include two, three, or morereleasable box connectors 944A connected to power conductors 946A thatterminate at releasable pin connectors 942A. Two, three, or more statorconductor cables 948A may be connected to power conductors 946A. Thestator conductor cables 948A are routed through the stator 840A toprovide power and voltage to the electromagnetic windings 842A. Thepower conductors 946A and stator conductor cables 948A may be configuredto connect the stator 840A in series with stator 860 and any otherstator that may be connected. The power conductors 946A and statorconductor cables 948A may be configured to connect the stator 840A inparallel with stator 860 and any other stator that may be connected. Thepower conductors 946A and stator conductor cables 948A may be configuredto connect the stator 840A in a hybrid series-parallel configurationwith stator 860 and any other stator that may be connected. The powerconductors 946A and stator conductor cables 948A may be configured withan addressable location that the controller 60 may control individually.The controller 60 may selectively power the stator on or off dependingon the inputs and sensor array 70 statuses.

A rotor 830A may be connected to rotor 810 at rotor hub 818. Rotor 830Amay have permanent magnets 834A mounted inside rotor disk 832A. Rotaryshaft 836A may be connected to rotor disk 832A or may be a unitaryconstruction. Rotary shaft 836A is connected to rotor disk 812 at rotorhub 818 by threaded connection, fasteners, other connecting parts (notshown) or a combination of methods.

A stator 860 may be connected to stator 840A and oil pump end sub 880 bythreading, fasteners, other connecting parts (not shown), or acombination of any of those methods. The stator 860 may haveelectromagnetic windings 862 wound radially about a stator core 864. Thestator core 864 may be slotted or non-slotted. The electromagneticwindings 862 may be wound with straight partial torus shape or with anangular partial torus shape. Power transfer terminal 960 may includetwo, three, or more releasable box connectors 964 connected to powerconductors 966 that terminate at releasable pin connectors 962. Two,three, or more stator conductor cables 968 may be connected to powerconductors 966. The stator conductor cables 968 are routed through thestator 860 to provide power and voltage to the electromagnetic windings862. The power conductors 966 and stator conductor cables 968 may beconfigured to connect the stator 860 in series with stator 840A and anyother stator that may be connected. The power conductors 966 and statorconductor cables 968 may be configured to connect the stator 860 inparallel with stator 840A and any other stator that may be connected.The power conductors 966 and stator conductor cables 968 may beconfigured to connect the stator 860 in a hybrid series-parallelconfiguration with stator 840A and any other stator that may beconnected. The power conductors 966 and stator conductor cables 968 maybe configured with an addressable location that the controller 60 maycontrol individually. The controller 60 may selectively power the statoron or off depending on the inputs and sensor array 70 statuses.

A rotor 870 may be connected to rotor 830A at rotor hub 838A. Rotor 870may have permanent magnets 874 mounted onto the surface or mountedinside rotor disk 872. Rotary shaft 876 may be connected to rotor disk872 or may be a unitary construction. Rotary shaft 876 is connected torotor disk 832A at rotor hub 838A by threaded connection, fasteners,other connecting parts (not shown) or a combination of methods.

Oil pump end sub 880 may be connected to the lower end of the stator860. The oil pump may describe a pump formed by an impeller anddiffuser, however any type of rotary pumping method may be utilized:external gear pump, internal gear pump, lobe pump, sliding vane pump,single screw pump, double screw pump, single stage centrifugal pump, ormultistage centrifugal pump, or any similar pump type. Oil pump shaft888 may be connected to rotor disk 872 at rotor disk hub 878 by threads,fasteners, connector parts (not shown), or a combination of methods.Power transfer terminal 980 may include two, three, or more releasablebox connectors 984 that terminate or may be connected to powerconductors (not shown) that are utilized to power addition equipment notshown; for example an additional oil pump.

The oil pump end sub 880 circulates oil through the axial flux motor 800to lubricate and transfer heat away from internal bearings. The rotaryshaft bearings 887 may be configured to support the rotors, reducevibration, and distribute radial and axial loading. The rotary shaftbearings 887 may be fluid film, rolling element, or other type bearingssuch as rotationally sliding sleeve and bushing bearings, ball bearings,roller bearings, spherical roller, tapered roller, or needle roller. Therotary shaft bearings 887 may be housed inside an open assembly thatallows lubricating fluid to flow through or a closed assembly with asealed structure. The rotary shaft bearings 887 may be any of the listedconfigurations or any combination thereof. The rotary shaft bearings 447may be constructed of bronze, steel alloy, nickel alloy, ceramics,graphite, composite materials, or any combination thereof.

Although the rotary shaft bearings 491 are shown in one location, therotary shaft bearings 491 may be placed in multiple locations within theaxial flux motor 800. The rotary shaft bearings 491 may be placedbetween front rotor 450 and back rotor 470. The rotary shaft bearing 491may be placed adjacent to front surface and back surface of each rotor.Each of the rotary shaft bearings 491 placed in the axial flux motor 800may be the same type of bearing or may be multiple types of bearings.

A heat exchanger 895 may be attached to the oil pump end sub 880. In anembodiment, the heat exchanger 895 may be a refrigeration assembly shownin FIG. 7D. In an embodiment, the heat exchanger 895 may be an oilreservoir 734 shown in FIG. 7D. In an embodiment, the heat exchanger 895may be oil channels with an outer housing shown in FIG. 7C.

A method of modifying the torque capacity for an axial flux motor 800attached to a pump assembly may be performed in the following manner.The oil pump end sub may be drained of oil and removed. A rotor may bedecoupled from a mating rotor and removed. A stator may be decoupledfrom a mating stator and removed. Decoupling the stator also disconnectsthe electrical power connections by disconnecting the releasable pinconnectors from the releasable box connectors. Multiple rotor and statorpairs may be decoupled and removed from the axial flux motor 800 thatmay be attached to a pump assembly.

The magnetic torque capacity may be decreased by removing one or morerotor and stator pairs and reassembling the remaining rotor and statorsto the axial flux motor 800.

The torque capacity may be increased by adding one or more rotor andstator pairs while reassembling the disassembled rotor and stators tothe axial flux motor 800.

The torque capacity of an embodiment of axial flux motor 800 may beincreased by decoupling stator 840A and stator 860 by unthreading,removing fasteners, removing mating hardware (not shown) or acombination of methods. The rotor 870 may be decoupled from rotor 830Aby unthreading, removing fasteners, removing mating hardware (not shown)from rotary shaft 876 and rotor hub 838A.

An assembly of stator 840B and rotor 830B may be added to axial fluxmotor 800. Stator 840B may be coupled to stator 840A. Rotor 830B may becoupled to rotor 830A at rotor hub 838A. Stator 860 may be coupled tostator 840B. Rotor 870 may be coupled to rotor 830B at hub 838B. The oilpump end sub 880 may be connected to stator 860. The oil pump shaft 888may be connected at rotor disk hub 878.

The torque capacity of an embodiment of axial flux motor 800 may bedecreased utilizing the same method but removing a stator and rotorinstead of adding a stator and rotor.

The axial flux motor configurations shown in FIGS. 7A-D and FIG. 8 maybe used for axial flux motor 50 shown in FIG. 1.

The rotor and stator configurations shown in FIG. 2, FIG. 3, FIG. 4,FIG. 5, and FIG. 6 may be used inside the housing of axial flux motorshown in FIGS. 7A-D and FIG. 8.

In an aspect, disclosed herein is an electronic submersible pump (ESP)system, comprising an axial flux motor (for example and withoutlimitation a modular axial flux motor comprising a plurality of rotor(s)and stator(s) assemblies/modules, for example has shown in FIG. 8); sealcoupled to the axial flux motor; and a pump coupled to the seal. The ESPsystem can further comprise a pump a pump intake coupled to the pump;and a pump exit coupled to the pump. In an aspect, one or morecomponents of the seal (including but not limited to a thrust bearing)and the axial flux motor are combined within a common housing, forexample to form a sealed axial flux motor. In an aspect the ESP systemis configured for a high temperature operating environment, for examplea high bottomhole temperature (BHT) in a hydrocarbon producing wellboresuch as in a range of from about 200° F. to about 500° F., alternativelyfrom about 300° F. to about 500° F., or alternatively from about 400° F.to about 500° F.

In an aspect, disclosed herein is a submersible ESP system, comprising asubmersible axial flux motor assembly compromising one or more modules(e.g., an assembly of rotor(s) and stator(s) as shown in FIG. 8) of anaxial flux modular motor; a seal coupled to the submersible axial fluxmotor having rotationally connection of the shafts; a pump intakecoupled to the seal having rotationally connection of the shafts; a pumpintake coupled to the pump having rotationally connection of the shafts;and a pump exit coupled to the pump. In an aspect, one or morecomponents of the seal (including but not limited to a thrust bearing)and the axial flux motor are combined within a common housing, forexample to form a sealed axial flux motor. In an aspect the ESP systemis configured for a high temperature operating environment, for examplea high bottomhole temperature (BHT) in a hydrocarbon producing wellboresuch as in a range of from about 200° F. to about 500° F., alternativelyfrom about 300° F. to about 500° F., or alternatively from about 400° F.to about 500° F.

ADDITIONAL DISCLOSURE

The following is provided as additional disclosure for combinations offeatures and aspects of the present invention.

A first embodiment, which is a cooling system for an electricsubmersible pump (ESP) system, comprising a submersible axial flux motorassembly compromising a stator and a rotor disposed within a motorhousing and having an axial gap between the stator and rotor, whereinthe stator has a plurality of stator windings, wherein the rotor has aplurality of permanent magnets, and wherein the rotor has a rotaryshaft, and a heat exchanger system coupled to the axial flux motorassembly to remove heat from the axial flux motor.

A second embodiment, which is the cooling system of the firstembodiment, wherein the heat exchanger system comprises a heat pump.

A third embodiment, which is the cooling system of the first or thesecond embodiment, wherein the heat pump further includes, but is notlimited to a condenser, an evaporator, a compressor, and a coolingfluid.

A fourth embodiment, which is the cooling system of any of the firstthrough the third embodiments, wherein the heat pump circulates thecooling fluid in the motor housing to remove heat from the axial fluxmotor to an ambient environment within a wellbore.

A fifth embodiment, which is the cooling system of the third or thefourth embodiment, wherein the cooling fluid is a dielectric fluid,wherein the dielectric fluid is one of mineral oil, synthetic oil,castor oil, silicone oil, oil containing nanoparticles, and anycombination thereof.

A sixth embodiment, which is the cooling system of the fourth or thefifth embodiment, wherein the cooling fluid is circulated in the axialgap between each stator and rotor.

A seventh embodiment, which is a heat exchanger module of an axial fluxmodular motor of a submersible ESP system, comprising a submersibleaxial flux motor assembly compromising two or more detachable motormodules of an axial flux motor coupled together, wherein each motormodule includes at least one stator and one rotor having a rotary shaft,and the rotary shafts of the two or more modules rotationally coupledtogether, and a heat exchanger module of an axial flux modular motorcomprising a detachable housing, wherein the detachable housing has afirst connection and a second connection and wherein the firstconnection and second connection are each connectable to one of a firstmotor module, a second motor module, or an end cap.

An eighth embodiment, which is the heat exchanger module of the seventhembodiment, wherein the heat exchanger module comprises a heat pump.

A ninth embodiment, which is the heat exchanger module of the seventh orthe eighth embodiment, wherein the heat pump further includes, but isnot limited to a condenser, an evaporator, a compressor, and a coolingfluid.

A tenth embodiment, which is the heat exchanger module of the ninthembodiment, wherein the heat pump circulates the cooling fluid in themotor housing to remove heat from the axial flux motor to an ambientenvironment within a wellbore.

An eleventh embodiment, which is the heat exchanger module of the ninthor the tenth embodiment, wherein the cooling fluid is a dielectricfluid, wherein the dielectric fluid is one of mineral oil, syntheticoil, castor oil, silicone oil, oil containing nanoparticles, and anycombination thereof.

A twelfth embodiment, which is the heat exchanger module of the tenth orthe eleventh embodiment, wherein the cooling fluid is circulated in anaxial gap between each stator and rotor.

A thirteenth embodiment, which is a heat exchanger system for an ESPsystem, comprising a submersible axial flux motor assembly compromisinga stator and a rotor disposed within a motor housing and having an axialgap between the stator and rotor, wherein the stator has a plurality ofstator windings, wherein the rotor has a plurality of permanent magnets,and wherein the rotor has a rotary shaft, and a heat exchanger systemcoupled to the axial flux motor assembly and comprising a refrigerationcycle comprising a refrigerant.

A fourteenth embodiment, which is the heat exchanger system of thethirteenth embodiment, wherein the refrigerant circulates through themotor housing and cools the rotor and stator.

A fifteenth embodiment, which is the heat exchanger system of thethirteenth or the fourteenth embodiment, further comprising an internaloil pump, a volume of cooling oil, and a circulation path, wherein therefrigerant exchanges heat with the cooling oil.

A sixteenth embodiment, which is the heat exchanger system of any of thethirteenth through the fifteenth embodiments, wherein at least a portionof a circulation path is disposed within the motor housing and coolingoil circulates through the portion of the circulation path disposedwithin the motor housing to cool the stator and rotor.

A seventeenth embodiment, which is the heat exchanger system of any ofthe thirteenth through the sixteenth embodiments, wherein the coolingoil is a dielectric fluid, wherein the dielectric fluid is one ofmineral oil, synthetic oil, castor oil, silicone oil, an oil containingnanoparticles, and any combination thereof.

An eighteenth embodiment, which is the heat exchanger system of thefifteenth embodiment, wherein the internal oil pump is releasablycoupled to the rotary shaft and wherein the internal oil pump is one ofimpeller and diffuser, external gear pump, internal gear pump, lobepump, sliding vane pump, piston pump, single screw pump, double screwpump, single stage centrifugal pump, or multistage centrifugal type.

A nineteenth embodiment, which is the heat exchanger system of thefifteenth embodiment, wherein the circulation path includes the axialgap between each stator and rotor, a radial gap between the housing andthe rotor, a cooling path through the stator, and the internal oil pump.

A twentieth embodiment, which is the heat exchanger system of any of thethirteenth through the nineteenth embodiments, wherein the refrigerationcycle includes, but not limited to a compressor, a radiant portion, anexpansion valve, and an evaporator having a cooling coil, wherein thecompressor compresses refrigerant and pumps the compressed refrigerantto the radiant portion to exchange heat with the radiant portion,through an expansion valve where the refrigerant expands to a gas andflows through the cooling coil to exchange heat with the cooling oil ina reservoir and return to the compressor.

A twenty-first embodiment, which is the heat exchanger system of thefifteenth embodiment, wherein the internal oil pump is formed on a faceof a rotor disk, wherein the face of the rotor disk forms an impellervane, wherein the impeller vane may include a curved path or a straightpath between a plurality of permanent magnets, and wherein the permanentmagnets are mounted onto the surface of a rotor disk or fixed into therotor disk.

A twenty-second embodiment, which is the heat exchanger system of thetwenty-first embodiment, wherein the shape of the permanent magnet andspace between two adjacent permanent magnets act as the impeller vaneproviding radially outward path of cooling fluid in the rotor and thereturn passage of cooling fluid passing through the stator radiallyinward.

While several embodiments have been provided in the present disclosure,it should be understood that the disclosed systems and methods may beembodied in many other specific forms without departing from the spiritor scope of the present disclosure. The present examples are to beconsidered as illustrative and not restrictive, and the intention is notto be limited to the details given herein. For example, the variouselements or components may be combined or integrated in another systemor certain features may be omitted or not implemented.

Also, techniques, systems, subsystems, and methods described andillustrated in the various embodiments as discrete or separate may becombined or integrated with other systems, modules, techniques, ormethods without departing from the scope of the present disclosure.Other items shown or discussed as directly coupled or communicating witheach other may be indirectly coupled or communicating through someinterface, device, or intermediate component, whether electrically,mechanically, or otherwise. Other examples of changes, substitutions,and alterations are ascertainable by one skilled in the art and could bemade without departing from the spirit and scope disclosed herein.

What is claimed is:
 1. A cooling system for an electric submersible pump(ESP) system, comprising: a submersible axial flux motor assemblycompromising a stator and a rotor disposed within a motor housing andhaving an axial gap between the stator and rotor, wherein the stator hasa plurality of stator windings, wherein the rotor has a plurality ofpermanent magnets, and wherein the rotor has a rotary shaft; and a heatexchanger system coupled to the axial flux motor assembly to remove heatfrom the axial flux motor.
 2. The cooling system of claim 1, wherein theheat exchanger system comprises a heat pump.
 3. The cooling system ofclaim 2, wherein the heat pump comprises a condenser, an evaporator, acompressor, and a cooling fluid.
 4. The cooling system of claim 3,wherein the heat pump circulates the cooling fluid in the motor housingto remove heat from the axial flux motor to an ambient environmentwithin a wellbore.
 5. The cooling system of claim 4, wherein the coolingfluid is a dielectric fluid, wherein the dielectric fluid comprisesmineral oil, synthetic oil, castor oil, silicone oil, oil containingnanoparticles, or any combination thereof.
 6. The cooling system ofclaim 5, wherein the cooling fluid is circulated in the axial gapbetween each stator and rotor.
 7. A heat exchanger module of an axialflux modular motor of a submersible ESP system, comprising: asubmersible axial flux motor assembly compromising two or moredetachable motor modules of an axial flux motor coupled together,wherein each motor module includes at least one stator and one rotorhaving a rotary shaft, and the rotary shafts of the two or more modulesrotationally coupled together; and a heat exchanger module of an axialflux modular motor comprising a detachable housing; wherein thedetachable housing has a first connection and a second connection andwherein the first connection and second connection are each connectableto one of a first motor module, a second motor module, or an end cap. 8.The heat exchanger module of claim 7, wherein the heat exchanger modulecomprises a heat pump.
 9. The heat exchanger module of claim 8, whereinthe heat pump further comprises a condenser, an evaporator, acompressor, and a cooling fluid.
 10. The heat exchanger module of claim9, wherein the heat pump circulates the cooling fluid in the motorhousing to remove heat from the axial flux motor to an ambientenvironment within a wellbore.
 11. The eat exchanger module of claim 10,wherein the cooling fluid is a dielectric fluid, wherein the dielectricfluid comprises mineral oil, synthetic oil, castor oil, silicone oil,oil containing nanoparticles, or any combination thereof.
 12. The heatexchanger module of claim 11, wherein the cooling fluid is circulated inan axial gap between each stator and rotor.
 13. A heat exchanger systemfor an ESP system, comprising: a submersible axial flux motor assemblycompromising a stator and a rotor disposed within a motor housing andhaving an axial gap between the stator and rotor, wherein the stator hasa plurality of stator windings, wherein the rotor has a plurality ofpermanent magnets, and wherein the rotor has a rotary shaft; and a heatexchanger system coupled to the axial flux motor assembly and comprisinga refrigeration cycle comprising a refrigerant.
 14. The heat exchangersystem of claim 13, wherein the refrigerant circulates through the motorhousing and cools the rotor and stator.
 15. The heat exchanger system ofclaim 13, further comprising an internal oil pump, a volume of coolingoil, and a circulation path, wherein the refrigerant exchanges heat withthe cooling oil.
 16. The heat exchanger system of claim 13, wherein atleast a portion of a circulation path is disposed within the motorhousing and cooling oil circulates through the portion of thecirculation path disposed within the motor housing to cool the statorand rotor.
 17. The heat exchanger system of claim 13, wherein thecooling oil is a dielectric fluid, wherein the dielectric fluidcomprises mineral oil, synthetic oil, castor oil, silicone oil, an oilcontaining nanoparticles, or any combination thereof.
 18. The heatexchanger system of claim 15, wherein the internal oil pump isreleasably coupled to the rotary shaft and wherein the internal oil pumpis one of impeller and diffuser, external gear pump, internal gear pump,lobe pump, sliding vane pump, piston pump, single screw pump, doublescrew pump, single stage centrifugal pump, or multistage centrifugaltype.
 19. The heat exchanger system of claim 15, wherein the circulationpath includes the axial gap between each stator and rotor, a radial gapbetween the housing and the rotor, a cooling path through the stator,and the internal oil pump.
 20. The heat exchanger system of claim 13,wherein the refrigeration cycle comprises a compressor, a radiantportion, an expansion valve, and an evaporator having a cooling coil,wherein the compressor compresses refrigerant and pumps the compressedrefrigerant to the radiant portion to exchange heat with the radiantportion, through an expansion valve where the refrigerant expands to agas and flows through the cooling coil to exchange heat with the coolingoil in a reservoir and return to the compressor.